Conventionally, there has been widely used a roller type conveyance device that includes drive rollers which are driven to rotate by appropriate actuators and rotatable free rollers, the drive rollers and the free rollers being arranged thereon, and conveys an object by transmitting the rotational force of the drive rollers to the object (see PTL 1, for example).
In such a conveyance device, in order to prevent an object being conveyed from falling off, the number of rollers arranged thereon is increased to make a gap between the rollers narrow. In addition, in order to prevent an object from slipping on the rollers, the ratio of the drive rollers in all of the rollers is increased.